1. Field
The present application relates to an observation device observing a sample cultured in a culture vessel, and a wavelength limiting filter for the observation device.
2. Description of the Related Art
Conventionally, a phase-contrast microscope or the like is known as an observation device observing a sample cultured in a culture vessel (for example, refer to Patent Document 1: Japanese Unexamined Patent Application Publication No. H11 -84260). There are various microorganisms, cells, and so on as the samples observed by the observation device as stated above.
Incidentally, it is often the case that an additive such as a pH indicator is added to a culture medium, for the culture of the samples such as the above-stated microorganisms and cells. There are additives such as the pH indicator having characteristic optical absorption properties. Accordingly, there are cases when brightness or a way how it looks like of the sample to be observed may change resulting from the additive. It is possible to correspond to such a change when a visual observation by a person is performed because the brightness, contrast, and so on are appropriately adjusted by the person. However, there is a problem that it is impossible to distinguish whether various changes occurred on an image is resulting from the change of the sample or resulting from the additive, because the brightness and the contrast of a generated image may change when an automatic observation is performed by using an imaging apparatus such as a camera.
Propositions of an observation device and a wavelength limiting filter for the observation device according to the present application are to suppress a change of an image resulting from an additive, and to enable to generate an appropriate image in an automatic observation.